code: def test_efficient_volatility():
      d = d_pass[4]
      pf = build_portfolio(**d)
      efficient_volatility_weights = np.array(
          [0.0, 0.5325563159992046, 0.4674436840007955, 0.0]
      )
      ef_opt_weights = pf.ef_efficient_volatility(0.191)
      assert np.allclose(
          ef_opt_weights.values.transpose(),
          efficient_volatility_weights,
          atol=weak_abse,
      )
  
imports: import datetime
  import os
  import pathlib
  import matplotlib.pylab
  import numpy
  import pandas
  import pytest
  import quandl
  import yfinance
  from finquant.efficient_frontier import EfficientFrontier
  from finquant.portfolio import Portfolio, build_portfolio
  from finquant.stock import Stock
label_desc: Use image node_id 13 for calling a global function with example usage: test_efficient_volatility() without return types